You set the value of AlwaysShowMenu to 1 in the following registry path to let Microsoft Lync 2013 or Microsoft Skype for Business always display a menu bar in the main window:HKCU\SOFTWARE\MICROSOFT\OFFICE\15.0\LYNCAfter you restart Lync 2013 or Skype for Business, the menu bar is displayed. However, if you perform the following operations, the menu bar disappears.
You click Options in the Tools menu.
You click the OK button in the pop-up window.
Note If you click Show Menu Bar in the Show Menu list near the "Gear" icon, the menu bar appears until Lync 2013 or Skype for Business is restarted.
To resolve this issue, install the April 14, 2015 update (KB2889923) for Microsoft Skype for Business.
Note Microsoft Lync 2013 will be upgraded to Skype for Business from April 2015.